Re: Calibrating for CCD/CMOS noise

[Herb Chong]

to my eyes, there is a lot of noise in the "without NR" that would have to 
be removed in Photoshop. lightning at that distance looks a lot like noise 
to simplistic algorithms that mostly are focused on eliminating hot pixels. 
i wonder if any other DSLR would far better. i think without smarter noise 
reduction algorithms, and there are plenty out there in other applications, 
that you're not going to get better. doing "manual" dark field subtraction 
wouldn't be terribly effective except for hot pixels.

Herb...
----- Original Message ----- 
From: "Jostein" <[EMAIL PROTECTED]>
To: <pentax-discuss@pdml.net>
Sent: Tuesday, January 25, 2005 12:44 PM
Subject: Re: Calibrating for CCD/CMOS noise


I've uploaded some samples, so you can see what it was like.
Here's one with noise reduction turned on:
http://www.oksne.net/lyn/lyn_med_nr.jpg
And a 1:1 detail from around the lightning:
http://www.oksne.net/lyn/lyn_med_nr_detalj.jpg
Here's one without noise reduction:
http://www.oksne.net/lyn/lyn_uten_nr.jpg
And a 1:1 detail:
http://www.oksne.net/lyn/lyn_uten_nr_detalj.jpg
The shot with NR is f/9, 30 s, at ISO 400.
The shot without NR is f/10, 30s, at ISO 200.
Conversion from raw file done with photoshop CS.
I believe the noise would have shone through even with a wider aperture. 
What do you think?